JP2008079446A - Rotary electric machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To further enlarge a variable range of output characteristics in a rotary electric machine capable of adjusting output by increasing/decreasing magnetic flux passing between a stator and a rotor. <P>SOLUTION: An armature coil wound on the stator 6 is constituted of first coils Lu1 (Lv1 and Lw1) and second coils Lu2 (Lv2 and Lw2), which are connected in series. Two terminals U1 (V1, W1) and U2 (V2, W2) are arranged to select a state where current is made to flow to both coils or a state where current is made to flow only to one coil. An increase/decrease range of the number of valid conductors by a difference in the number of widings can be combined to a magnetic flux increase/decrease range by stator movement. The number of rotations and an adjusting range of torque in the rotary electric machine can be enlarged much more. Characteristics of the electric motor and power generator can be improved remarkably, and coverage of one machine becomes large. It becomes unnecessary to prepare variable types of different ratings, so that productivity improves. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a rotating electrical machine that can freely adjust output characteristics.

Conventionally, there is a rotating electrical machine used as an electric motor or a generator, for example, an electric motor, in which the output can be adjusted by changing the facing area between the stator and the rotor. For example, the rotor is moved in the axial direction. In this case, the overlapping area between the rotor and the stator is increased or decreased (see, for example, Patent Documents 1 and 2), and the gap between the opposing surfaces of the rotor and the stator is adjusted. (For example, refer to Patent Document 3).
JP-A-5-300712 JP-A-6-141401 JP 2004-80847 A

  In the electric motor as described above, the magnetic flux is increased / decreased only by increasing / decreasing the facing area of the rotor and the stator and increasing / decreasing the gap, and there is a problem that the variable range of the output characteristics is narrow. The same applies to a generator as a rotating electrical machine.

  In order to solve such a problem, the present invention realizes further widening the variable range of output characteristics in a rotating electrical machine that can adjust the output by increasing or decreasing the magnetic flux passing between the stator and the rotor. In the rotating electrical machine having a rotor, a stator provided coaxially with respect to the rotor, and a magnetic flux adjusting means for increasing or decreasing a magnetic flux passing between the rotor and the stator, the magnetic flux adjusting means includes: A stator moving means for changing the position of the stator with respect to the rotor, and an armature coil wound around the stator so that the number of turns can be selected in at least two stages, and the number of turns of the armature coil And coil winding number selection means for selecting.

  In particular, the stator moving means displaces the surface of the stator that faces the magnetic pole surface of the rotor between a position that substantially completely overlaps the magnetic pole surface in the axial direction and a position that deviates by a predetermined amount in the axial direction. The stator may be moved as described above. Further, the same phase of the armature coil is wound in at least two parts on the same tooth of the stator, or the same phase of the armature coil is wound in the circumferential direction of the stator. Each of the phases of the armature coil is wound so that one of the ranges is adjacent to another range in the other phase. It is good that it is lined.

  As described above, according to the present invention, the stator is moved with respect to the rotor to increase or decrease the magnetic flux passing between them, and the number of turns of the armature coil wound around the stator can be selected in at least two stages. Therefore, the change in the number of effective conductors due to the difference in the number of windings can be combined with the increase / decrease in the magnetic flux due to the movement of the stator, and the adjustment range of the rotation speed and torque in the rotating electrical machine can be further widened. The characteristics of the electric motor, the generator, etc. can be greatly improved, and the range of application of one unit becomes wider, so there is no need to prepare various types of devices with different ratings.

  In particular, by displacing the opposing surface of the stator to the magnetic pole surface of the rotor in the axial direction with respect to the magnetic pole surface, the opposing area where the magnetic flux passes between the stator and the rotor is based on the axial displacement of the yoke. It can be changed and is easy to control.

  In addition, the same phase of the armature coil is wound around the same teeth (one tooth) of the stator, for example, in two parts, so that a tap is provided between the two divided coils and selective connection is made. By connecting via a connector, the selective connector is connected and current is passed in series through the two coils, and when the selective connector is released and current is passed through only one coil via the tap. The number of effective conductors of the armature coil can be easily changed with a simple winding structure.

  Further, even if the in-phase armature coils are wound in at least two ranges divided in the circumferential direction of the stator, the same effects as described above can be obtained. In this case, the winding is wound so that one of the ranges is adjacent to another range in the other phase, so that in a use mode in which no current flows in one of the ranges in any phase, Large iron loss can occur in the teeth of a range, but by winding next to another range in another phase, even if the current in any phase does not flow, Since the magnetic flux due to other phases is generated in the range, the iron loss in the teeth can be reduced.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic cross-sectional view showing an example applied to drive wheels W of an electric automobile. In the figure, a fixed support shaft 2 is projected and fixed on a vehicle body 1, and a rotor 4 is rotatably supported on the fixed support shaft 2 via a pair of bearings 3a and 3b. Drive wheels W are attached to the outer periphery of the rotor 4 via wheels.

  The rotor 4 is formed with large and small boss portions 4a and 4b coaxially with the support shaft 2, and a space between the boss portions 4a and 4b is opened to the vehicle body 1 side. On the inner peripheral surface of the large-diameter boss portion 4a, a plurality of magnets 5 in which N and S poles are arranged in the circumferential direction are disposed as shown in FIG. Moreover, the stator 6 is provided so that it may be received in the space by both boss | hub parts 4a * 4b.

  The stator 6 integrally includes a stator core 8 fixed to the outer peripheral surface of the annular member 7 positioned on the small-diameter boss portion 4b side, and an armature coil 9 wound around the plurality of teeth 8a. . The stator 6 thus configured and the rotor 4 constitute a motor M as a rotating electrical machine to which the present invention is applied.

  The annular member 7 is slidably supported on a vehicle body 1 by a guide shaft 11 projecting and fixed toward the rotor 4, and a drive shaft 12 a of a motor-driven actuator 12 attached to the vehicle body 1, for example. The reciprocation is enabled in the axial direction of the support shaft 2 (rotor 4) by the movement.

  Thus, by driving the actuator 12, the annular member 7, that is, the stator 6, enters and exits the space between the boss portions 4a and 4b. The moving direction of the stator 6 is the axial direction of the rotor 4, and the amount of displacement of the stator 6 with respect to the magnetic pole surface 5 a of the magnet 5 is as shown in FIG. The projecting end face 6a may be between two positions, ie, a position where the projecting end face 6a completely overlaps in the axial direction of the rotor 4 and a position completely deviated as indicated by a two-dot chain line in the figure. Note that the amount of displacement from the completely overlapping position is not limited to the completely deviated position in the illustrated example, and may be a position deviated by an arbitrary predetermined amount, for example, to a completely deviated position. When the displacement amount is set to 100%, it can be about 50%. In the case of the position of 50%, the overlapping amount of the magnetic pole surface 5a and the facing surface 6a in the rotor axial direction is halved.

  Next, the control procedure according to the present invention will be described with reference to the block circuit diagram of FIG. The illustrated motor M may be the same as a three-phase brushless motor.

  In the illustrated example, an inverter 21 constituting a transistor bridge circuit is connected to an in-vehicle battery BT as a power source, and three output lines corresponding to the U phase, the V phase, and the W phase are used as coil winding number selection means. It is connected to the motor M via phase-specific relays RLu, RLv, and RLw.

  In the motor M of the illustrated example, the armature coil 9 is wound separately for each phase into a first winding number and a second winding number, and each phase is star-connected. The winding state with respect to each tooth 8a is shown in FIG. Note that FIG. 2 shows the winding state over the entire circumference only for the U phase for the sake of explanation, but the V phase and the W phase are also wound together with the U, V, and W. Therefore, in the following description, the U phase is shown unless otherwise specified, and the other phases are the same (indicated by differences in subscripts) and the description is omitted.

  As shown in FIGS. 1 and 2, the first coil Lu1 is connected to the first terminal U1 for external connection, and the second coil Lu2 is connected in series between the first coil Lu1 and the neutral point terminal C. In addition to being connected, the nodes of both coils Lu1 and Lu2 are drawn out as second terminals U2 for external connection. Each of the terminals U1 and U2 may be a two-position selection contact of the relay RLu, and one of the terminals U1 and U2 is connected to the inverter 21 according to excitation / de-excitation of the relay RLu. When the first terminal U1 is connected, current flows through both the coils Lu1 and Lu2, and when the second terminal U2 is connected, current flows only through the second coil Lu2.

  Various winding methods for winding the armature coil 9 separately for each phase into the first winding number and the second winding number are conceivable, and FIG. 2 shows a first example. In FIG. 2, the first coil Lu1 is wound around the one tooth 8a with the first number of turns, and the second coil Lu2 is wound with the second number of turns. As a winding method, it can be stacked in the protruding direction of the teeth 8a or can be wound twice inside and outside, and the winding method is not particularly limited.

  In FIG. 2, the power supply side of each coil of each relay RLu, RLv, RLw provided corresponding to each phase is connected to the positive terminal of the battery BT, but the ground side is grounded via the transistor Q1. It is like that. The transistor Q1 is turned on / off by the control output of the control circuit ECU. The current detection sensor 22 is provided on the positive line of the battery BT, and the motor M is provided with a rotation speed (angle) sensor 23 for detecting the rotation speed (angle) of the rotor 4, and the current detection signal is controlled. The rotational speed (angle) signal is input to the current detection circuit 24 of the circuit ECU, and the rotational speed (angle) signal is input to the rotational speed detection circuit 25 of the control circuit ECU.

  In the control circuit ECU, each circuit necessary for performing a control to output a PWM signal for PWM controlling the motor M to the inverter 21 in accordance with these detection signals is provided as shown in the figure. A known control method in PWM control using these circuits may be used, and detailed description of the parts understood by the illustrated circuit names and signal lines will be omitted.

  For example, a signal corresponding to the depression amount of the accelerator pedal of the vehicle is input to the driving operation input circuit 26, and the duty corresponding thereto may be set as the control target value. The stator position control circuit 27 calculates the set position of the stator 6, and a position control signal corresponding to the calculated position is output from the position drive circuit 28 to the actuator 12. The actuator 12 drives the stator 6 and stops at the set position. Put it in a state. Thereby, as described above, the amount of overlap between the magnetic pole surface 5a and the facing surface 6a (the area of the portions facing each other; hereinafter referred to as the facing area) increases and decreases, and the magnetic flux passing through the facing area increases and decreases. The characteristics of the motor M can be a low rotation / high torque type when the facing area is increased, and a high rotation / low torque type when the facing area is small.

  Further, by selectively energizing / de-energizing the relays RLu, RLv, and RLw, it is possible to switch between two states in which current is supplied to both or only one of the coils Lu1 and Lu2. When the state of flowing current to both the coils Lu1 and Lu2 is selected, the motor characteristics of the high torque / low rotational speed type are obtained. On the other hand, when the state of flowing current only to Lu2 is selected, the low torque / high rotational speed type of motor is selected. It becomes a motor characteristic.

  The switching control is performed by switching on / off the transistor Q1 via a delay circuit 30 in the illustrated example, from a switching signal from the coil connection switching circuit 29 in the control circuit ECU. The coil connection switching circuit 29 may output a switching signal in accordance with a switch signal from an external selector switch. However, the switching signal in accordance with map control using duty, rotation speed, etc. May be output.

  By combining this coil connection switching control with the increase / decrease control of the facing area, a wider range of rotational speed and torque variable characteristics can be obtained. In particular, when various external conditions change from moment to moment as in an electric vehicle, it is possible to perform control utilizing the maximum characteristics of the motor at all times, resulting in efficient control, and for the battery BT having the same capacity. On the other hand, the one-time charging travel distance is extended, which can contribute to downsizing of the battery BT.

  In addition, by making both the coil connection switching control and the opposing area increase / decrease control high torque type, it is possible to make a higher torque type motor for those that only perform one of the controls. The torque can be increased. Therefore, when the maximum torque is designed to be the same, the motor can be reduced in size, and accordingly, the weight reduction of the vehicle is promoted, and the high rotation speed can be increased together with the reduction in the size of the motor.

  Next, a second example of the winding method of the armature coil 9 is shown in FIG. 4 corresponding to FIG. In addition, the same code | symbol is attached | subjected to the part similar to the said example of illustration, and the detailed description is abbreviate | omitted. In the second example, the second coil Lu2 (Lv2 · Lw2) is wound around the first range A in the circumferential direction of the stator 6, and the first coil Lu1 (Lv1 · Lw1) is set as the remaining range. The second range B is wound. Even if it does in this way, there can exist an effect similar to the above.

  A third example of the winding method of the armature coil 9 is shown in FIG. 5 corresponding to FIG. Also in this case, the same parts as those in the illustrated example are denoted by the same reference numerals and detailed description thereof is omitted. In this third example, each phase is wound in the same manner as in the second example, but the terminals U1 (V1 · W1) · U2 (V2 · W2) · neutral points of each phase. C is pulled out from a position equally divided in the circumferential direction of the stator 6 (120 ° pitch in the illustrated example). In this way, when a current is supplied only to the second coils Lu2, Lv2, and Lw2, the teeth on which the rest of the first coils Lu1, Lv1, and Lw1 are wound act as supplementary poles, and the magnetic flux Therefore, the output characteristics can be improved.

  The rotating electrical machine according to the present invention can greatly widen the variable range of the rotational speed and torque, and is useful as an electric motor, a generator, or the like.

It is typical sectional drawing which shows the example applied to the drive wheel W of the electric vehicle. It is explanatory drawing which shows the 1st example of the winding method to a stator. It is a circuit block diagram which shows the control point. It is explanatory drawing which shows the 2nd example of the winding method. It is explanatory drawing which shows the 3rd example of the winding method.

Explanation of symbols

4 Rotor 5 Magnet 6 Stator 8a Teeth 9 Armature coil 12 Actuator Lu1, Lv1, Lw1 First coil Lu2, Lv2, Lw2 Second coil RLu, RLv, RLw Relay

Claims (5)

In a rotating electrical machine having a rotor, a stator provided coaxially with respect to the rotor, and magnetic flux adjusting means for increasing or decreasing a magnetic flux passing between the rotor and the stator,
The magnetic flux adjusting means has stator moving means for changing the position of the stator with respect to the rotor, and in addition, an armature coil wound around the stator so that the number of turns can be selected in at least two stages; A rotating electric machine comprising coil winding number selection means for selecting the number of turns of a child coil.   The stator moving means displaces a surface of the stator that faces the magnetic pole surface of the rotor between a position that substantially completely overlaps the magnetic pole surface in the axial direction and a position that deviates by a predetermined amount in the axial direction. The rotating electric machine according to claim 1, wherein the stator is moved.   3. The rotating electrical machine according to claim 1, wherein the same phase of the armature coil is wound in at least two parts on the same tooth of the stator.   4. The rotation according to claim 1, wherein the same phase of the armature coil is wound in at least two ranges in the circumferential direction of the stator. 5. Electric.   5. The rotating electrical machine according to claim 4, wherein each phase of the armature coil is wound so that one of the ranges is adjacent to another range in another phase.

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